TOOK ME A COUPLE MONTHS TO LEARN but oh my god I am so ecstatic that a person like you has even seen my content. your videos are so damn awesome and researched to an incredible degree. to have one of my piss poor videos in your description is nothing short of an awesome honor. KEEP IT UP MAN!!! LOVED THE SHUTTLE VIDEO!!!!!

When asbestos is one of the least alarming components of your setup, you've accomplished something truly amazing.

You know it’s really hazardous when they knew it was hazardous in the 60s

I have a few personal rules I live by. As an Air Force program manager, my number one rule is "Never let an engineer get bored" Please dear god, if you work with or around engineers take this to heart. This video is the kind of stuff that happens when you let engineers get bored.

I'm a military systems engineer, former infantryman, and parachutist & jumpmaster. Your comment about reduicng dangerous operations to tedium really hit home. Boring is often very *good* ...

I can just see the project review meetings. NASA management: what the hell did you guys do? We could never use any of this! Rocketdyne engineers: well you said to make the engine with the highest ISP ever, you never said make the engine with highest ISP ever that DOESN’T kill everyone in a 5 mile radius

Fluorine: "Yo dawg, I heard you got electrons."

You know it's cool when an asbestos cladding is the safest part.

One of the things lots of people forget when it comes to rockets is that a 10% increase in thrust at liftoff could actually double your acceleration. Most rockets have a 1.1-1.3 to 1 thrust to weight ration which means at 1.1, about 90% of the thrust is being wasted just to cancel out gravity, only the last about 10% is actually changing the rocket’s velocity. So increasing it to 1.2 to 1 means it will leave the launch pad twice as fast.

Dimethyl mercury? I momentarily lost my ability to control YT, accidentally closed the window and just sat there saying "wtf" for a minute. That infamous nightmare fuel poisoning case wasn't on the skin, it was through a latex glove.

the issue of pumping molten lithium through a rocket in-flight is left as an exercise to the reader...

"That's right, we're going to build a rocket with a controlled metal fire. I already hate that sentence." LMAO! Was not expecting to fully laugh out loud at this video. 🤣🤣🤣

I worked at Rocketdyne for several years starting in the mid 70's. There was some interesting stuff.

32:33 "The nuclear reactor, laser research facility, plutonium lab, and other experiments at Aperture Scien-uuuhhh I mean S.S.F.L." I'm rolling... XD

TL;DR, a tube of unimaginable violence with a rocket nozzle on the end

Kerbal Space Program meets Portal meets Doom meets Derek Lowe's "Things I Won't Work With" blog meets XKCD's What If (except that Rocketdyne would be saying "What do you mean, 'if'?"). So many WTF's packed into one video. Makes you really appreciate life, while you have it.

The intro music was perfect. Mid-century super-science was fucking insane. "Welp, this can kill ya in 20 or 30 different, horrifying ways. Bound to give you at least 5 types of cancer just from staring at it. Really amazing specific impulse if you mix it with this other elements that is committing active warcrimes inside his heavily reinforced container as we speak. So anyway; we're going to need a few million liters of both in holding for our testing of this highly explosive rocket engine that's going to get us to Alpha Centaury within the next century by my calculations. I've got a 150,000 dollar grant which is basically one trillion in stupid iPad Kid money so we're just gonna smack these two things together right over there and see what happens. Gotta tell you, I sure do love the US of A!"

That rap was so fire, it burned through 10 inches of steel reinforced concrete and then 6 feet of gravel.

25:57 it took me until here to realise the test firing footage isnt actually filmed footage but CGI. Nice work.

Extremely well put together video, glad the VHS upload got used for something. It is aggressively 90's. With youtube we can share our suffering with others.

I think the PPE that was recommended in "Ignition" was a good pair of running shoes.

I am currently pursing a chemistry degree while working as a part-time firefighter. This video seems to be designed entirely to scare me.

My chem prof @ SU in the '70's recounted a similar barrel shoot at Oak Ridge way back in the day. Copper was being rationed so they fiddled with sodium filled iron pipe as a potential substitute for heavy power buss bars. In the end the full barrels of sodium were rolled down a hill into a pond while being shot at in motion. He recounted it as the best fireworks he'd ever seen, esp. if done at night.

When the meltdown occurred I was 2 months old and my family lived 1/2 mile from the reactor. Rocketdyne did not notify the residents nearby, there was no evacuation. My sweet grandmother died of stomach cancer from drinking the well water. We found out about the meltdown and other crimes 20 years later. I've had severe undiagnosable health problems most of my adult life, while Rocketdyne continues doing business! What a world we have made for each other!!

Minor nitpick - the best ISP from flown LH2/LOX engines is actually the RL-10B-2, which gets 465s. However, the expander cycle that enables this performance is only really usable at small scale, and as such engines using it tend to be vacuum-optimized upper stage engines only. (Aerospace engineer here who's fascinated to see someone finally cover this - it's amazing how hard it is to find good info on this ludicrous tripropellant engine - I'm only a bit into the video so far, so I'll add other notes in this comment if I see them)

I love the barely contained laughter as he's narrating. I kinda find it mind blowing that there were a group of folks that thought actually taking this concept from a thought experiment to building a test article was even a reasonable idea. Awesome video.

My goodness, that safety video at the end almost killed me. I used to work with liters of HF for peptide synthesis/cleavage. We used KelF lines to pump the gas, and liquid nitrogen to liquify it. I never had an accident, but I saw two no-injury accidents. Both employees were immediately fired. It was safe enough, if, if, you didn't make any mistake. Turning the wrong valve caused liquid HF to drop to the aluminum jack-stand, eat through that, and onto the slate lab surface, and etch that, all in a flow hood. Good times! Thankfully, the synthetic chemistry is now much more benign.

Thanks for giving me the motivation to read ignition which has been on my shelf for a while. Definitely a good book that I should have gotten around to reading earlier.

this whole video reads like a billy mays ad: "but wait, it gets WORSE!"

Nothing could have possibly prepared me for that Rocketdyne safety rap

51:30 I'm actually speechless... Those fonts, those colors. For that. Just.... fantastic. Even better than nineties sportswear. No, have to edit. That outtro beats it.

The book 'Ignition! An Informal History of Liquid Rocket Propellants' is simply superb, I implore everyone to go and read it.

Im pretty sure all this stuff was carried out at their test site around Simi Valley, CA, USA. My dad grew up in the valley right under the test site, unknowingly exposed to a nuclear meltdown, chemical tests like these, and the joy of wondering "did the russians finally nuke us?" then waiting a few moments to thing "Nope, just another Rocketdyne test fire"

can you imagine having to watch that music video at work with a straight face?

After I regained consciousness following that closing rap, I gave the vid (minus the ending) a thumbs-up.

I honestly didn't realize it was an animation at first. Top tier!

Speaking of good performing (and dangerous) rocket engines, I would like to see an analyses video about the feasibility and performance of a hypothetical Nuclear Salt Water Rocket. I feel like it doesn't get the love it deserves.

Yeah Fluorine IS great, we used to use a molecule based on Fluorine (Perfluorates among others) to make skis slide faster and win more medals. The cancer you caught from the fumes in the tuning room was simply a feature. :)

Great video! In the 1980s I worked at the Prototype Fast Reactor at Dounreay in northern Scotland. It was cooled by liquid sodium (another alkali metal). We used electrically trace heated pipes and vessels to keep the sodium molten, and argon cover gas to keep out oxygen. To stop the system clogging up with oxides from accumulated oxygen impurities, part of the sodium was circulated through a 'cold trap', where the sodium was regeneratively cooled and passed through a stainless steel basket, where sodium oxide precipitated. This kept oxide levels low and (importantly) kept the sodium freezing point close to its nominal 100 degrees C (or so). Anyway, great video, very enjoyable. See also John D Clark's book 'Ignition!', which is a great history of some wacky rocket fuel options that were investigated in the 50s and 60s.

The crimson red exhaust emanating orange fumes is by itself enough to make anybody recoil in terror, all 9 rings of hell is unleashed upon ignition. instead of hazard symbols, there should just be a "God cannot help you here" sign at the test facility entrance. if it wasn't for the existence of nuclear thermal rockets this could definitely be called the most dangerous rocket engine ever tested.

The description of the "burn pit" to the clip at 33:35 is amazing haha

PhD chemist here. Whenever I find a mistake, I will write it into this comment. 7:15 You made a mistake saying that the reaction between hydrogen and oxygen follows the formation of ions first. The reaction is in fact using a radical chain mechanism. 17:50 It doesn't decompose back into fluorine. It gets deprotonated, turning into F-, and then reacts with calcium to form CaF2, which is basically insoluble in the environment of the body. So basically, it pulls calcium out of everything that needs calcium, including your bones and the synapses of your nerves. That's why you treat a HF injury with calcium gluconate injections into the affected area. To give the fluoride something to attach to instead of, you know, the calcium you actually need. 32:40 You refer to the experiment being done at Aperture Science. This is in fact wrong. Tests like this were performed in the Black Mesa research facility. 33:20 At my old university, we would discard of pyrophoric old chemicals also by shooting them. We had a concrete block in the courtyard of the building, and hit them from a safe distance with a pellet rifle. Typical substances were things like tert-butyllithium. In small scales, this is actually pretty safe. 35:50 Regarding LiF's impact on the enviroment. It's likely that the fluoride will just precipitate as CaF2 once it hits water. The little bit of calcium dissolved in water, limescale for example, is enough to precipitate it. As to the lithium, it's basically harmless in small concentrations. 37:10 "A couple of drops to your skin might be fatal", is actually depicting it in a too harmless way. The chemist you're talking about was killed by it after less than 1 drop of it soaked through a protective glove. HgMe2 is one of the chemicals I will ever refuse to work with, and I've so far seen some weird dodgy shit already. 42:50 Uranium hexafluoride isn't gaseous at ambient conditions, it's a white solid. Those gas centrifuges operate under a partial vacuum at slightly elevated temperature. Tungsten hexafluoride is gaseous at ambient though. Additionally, UF6 usually isn't made using F2, instead, ClF3 is used. 49:20 Are you sure the radial cutting torches use thermite? My bet would be that they're a form of thermal lance, using oxygen gas and a metal. That concludes my list of mistakes found. Here's a few extra comments: 1. Your opinion about the square cube law showing up everywhere is the truest statement ever made. 2. I wonder if we could use the exhaust heat of an radioisotope generator, RTG, in a deep space mission to keep the lithium molten. Or, alternatively, use a lithium-sodium-potassium alloy to reduce the melting point. EDIT: Typo and correction from "glucamate" to "gluconate". That was an error caused by autocorrect I think. Or a brainfart of mine. Thanks for the correction anyway.

There was a very large tank of liquid fluorine up on the hill near us that was used in the late 70's and 80s for laser testing by TRW. Long after the tests ended that tank sat on the hill and nobody wanted to touch it. Finally during a safety review of what would happen if it burst and that liquid ran down the hill towards the town, TRW agreed to dispose of it. I made sure to leave the area for a few days while the pumped it out and transported it somewhere.

This is by far my new favorite channel. What I would have given to work for Aerojet Rocketdyne at the Santa Susanna Filed Laboratory.

The Soviets played with metal rocket fuels, too. I don't know much about it. But a professor at uni told me he was part of the project and the probability of the propellant disassociating into ions after their initial reaction reduced the total output to uselessness. Or... so was my limited understanding.

My dad used to work for Bell systems and he would bring those monthly safety and instructional videos home and we would watch him and just fall over laughing, very similar to the clip at the end

this is so far one of the best videos I've ever seen, truly amazing stuff you presented here

This is the funniest name I’ve come across on KZfaq!! Very very funny and clever!

Holy damn. Having a good chemistry knowledge as you started talking about the propellants involved I slid further and further into incredulity at how freaking *MENTAL* the concept is. Rocketdyne: "How can we make the most absurdly dangerous rocket engine ever?"

You mentioned "awkward units"... We write formulas for colored glass in grams of coloring chemicals / 100 pounds of glass. Why? Because glass "batch" comes in 25lb bags, and good old Ohaus triple-beam balances came mostly in grams, especially if you shopped on the used lab equipment market.

Years ago my group was the backup for a module the Ruzzians were supposed to be building. When we went to Florida for a site visit to see where to put our test equipment we went thru the hangar where everything was to be put together for launch. The scariest part of the briefing was what to do if the sirens went off if there was a fuel spill. Look for the wind sock and run upwind FAST. If evacuation was in one direction it was into a swampy area. They told us don’t worry about the alligators, it’s worse having the fuel get on us.

this is my favorite rocket propellant, because it makes any chemist i meet recoil in horror when i tell them what it is

I want one! 🤤

I'm amazed they got a functioning test with this combination of chemicals in use.

Ive been binging your videos since i just found your channel 👍 really interesting stuff and i really appreciate you citing your sources, makes following along more interesting

i just gotta say, starting this video with "Science is Fun" from the Portal 2 soundtrack was a stroke of genius.

Yayyyyy RS-25 discussion in the first 5 minutes

As soon as I saw the orange exhaust smoke in the intro sequence, I was like "Yep, that's gonna be toxic.". Edits post-video: As to the future of upper stage propellant systems, with the renewed interest in nuclear Thermal rockets (NTRs), NASA is looking at utilizing NTRs for Mars transport vehicles that use LH2 as the propellent. There are lots of studies that go into it, but there are several designs that see around 800-900s of ISP, twice that of thermal rockets, and all being a monoprop solution. As I was going through uni for aerospace engineering with a rocket propellent focus, I took a particular interest in magnetic nozzle designs for nuclear fusion rocket motors. There's a high probability if you look up a decent amount of research on pulsed magnetic nozzles, you'll read some research from some of my professors. Despite their complexities, fusion rockets have seen the potential of ISPs as high as 10,000s, while also being a part of a long-term habitation's power generation source. If we ever get the complexities of fusion figured out, I'm fairly certain that's the direction the industry will go.

Such a well done video. Great Job. Found your channel for the first time with this. Looking forward to checking out the rest. That outcome though... What a laugh

The SRE used liquid sodium as a coolant. NaK was used in the fuel rods as a thermal bonding material- something that is sometimes still done today. The problem was with the material used to cool the sodium pumps- a liquid hydrocarbon known as tetralin. A crack in one of the pumps caused tetralin to enter the sodium loop and break down, causing carbon to plug up some of the cooling channels, resulting in the subsequent partial meltdown. NaK was subsequently used as the pump coolant after the reactor was repaired.

I used to do wireline in the oil fields. We used fluorine in our down hole chemical cutters. It was crazy. It would instantly cut a pipe as soon as we set it off. Leaving a smooth cut edge like it was cut with a water jet. Wild stuff. I believe the cutting head was made from beryllium. I could be wrong on that. In short, a small charge burned and pushed a piston in the tube with the fluorine mix into the cutting head and the head had a bunch of holes in a line around the heads midpoint. Basically making a chemical "saw" that burned through the pipe. A far cleaner option than a cutting charge, two shape charges facing each other causing the blast to shoot out radially and fairing the pipe out. Requiring milling to do more work. Only other option is plasma cutting. But a single use plasma cutter costs $40k, back in 2013. I am sure that price is much higher now. We could do a chemical cut for $20k for the whole job. A plasma cut would be $60-100k all said and done.

Curious Marc recently published a video on AGC fly-by-wire ( they have access to actual hardware and are now retrieving the software from the memory). Multiple viewers sited your video on the topic in the comments. Your channel is about to blow up.

I think I've watched this 5 times or more since it was posted. Love the narration. This story is an impressive walk down a road of thought "shouldn't, but someone had to try it" progressively getting more absurd with each iteration. I admire those who dared to fail so greatly, as that is how we make the big leaps required to break dogma of the beaten path. Some may not understand this philosophically core need to risk to improve, but the world wasn't built on the backs and minds unwilling to dare greatly.

I don't know what's going on, but when someone mentions fluorine, I get pretty excited about what might come next.

Generally, higher temperatures does mean higher exhaust velocities, and therefore better isp. But, if burning the fuel stoichiometrically (and therefore, as hot as possible) increases the mass of the average exhaust molecule, it can be a net loss. This is why Hydrogen / Oxygen rocket engines run not just a bit fuel rich, but extremely fuel rich; more hydrogen = lighter exhaust = more isp. EDIT: This video is fantastic btw. Great work! EDIT 2: Oh look, you guessed exactly this as soon as I pressed play again.

Pulled me from across the house when I heard "mixed with florine". No, thought I. Surely he said chlorine. He must have said chlorine. What kind of MADMAN would....Oh. Rocket scientists in the sixties. MMMyep. Sounds about right. With hydrogen. Mmmyep. That would track. We're talking about the same fellas who turned a manhole cover into the fastest projectile ever fired with a mininuke underground in a long barrel...err..tunnel.

What an amazing, well researched video. I've learnt so much and enjoyed the presentation so much. Hitting the Thanks button hardly seems enough. Thankyou.

I wish I could say the video at the end took me by surprise, but I was a teenager in the 90s. There had to have been a single company making every training video back then. From a fast food restaurant to an industrial plant that built titanium knee and hip replacements, almost all of them were just like that video.

At 38:35, you mention it on top of a saturn v. But the image mentions a 260inch SRM with an SIVB. This was a proposed saturn 1B replacement vehicle, witht the first being replaced with a monolithic 260 inch wide SRB (which, fun fact, was tested, and was so massive that they didnt even bother removing it from the test stand and you can visit it today at the now abandoned rocketdyne dade facility)

I just finished reading Ignition and was curious for more detail on the fluorine rocket tests. Your recreation of the test stand adds some amazing context. Really well done. I recall Clark saying something like there are outside odds that CFl3 might be an oxidizer for the future. Your video adds nuance to that speculation. You not only did justice to the primary sources but even expanded and enriched them. Great work!

Very fascinating information. It chimes with me because i lived at the other end of simi for a few years up to 2000, and have driven past the rocketdyne facility a few times. I had heard that end of town was polluted by the facility but didnt know anything about the nuclear horrors of the pit burnings of nuclear waste or this guided toxic waste projectile untill long after i left. You occasionally heard what seemed to be a low flying jet aircraft roaring but neither getting closer or going away. One day i was driving down the freeway and heard the same , and saw a tall narrow jet of smoke rising into the sky from the far side of the valley. It turned out they tested the shuttle boosters there, occasionally. I also liked the safety video. It reminded me of an occasion when we were having a total company meeting to cover some of the problems, and some higher up had come across to explain what was going on. We were all sat in rows with baited breath , and then the bosses ( 4) all strode in line from the back up to the front spread out in a line with their backs to us. Then they suddenly donned hats and started singing a modified version of YMCA while dancing around a la village people. I remember clearly to this day , the guy behind me muttering " oh God....we are doomed". For context the facility was called the AMC, so they sere singing Y(why) AMC. All a bit contrived, but thats management for you

The 3d animation is absolutely incredible. It's very difficult to distinguish from reality with the main giveaways being a slight pixelation of the fog/condensation effects, lack of shaking of loose hoses, and the overall cleanliness of the workshop

Why would they bother talking about safety? If you care in the slightest about safety you would have booked a flight out of the country before finishing the report's abstract.

Spicy orange cloud in the intro means this video is going to be awesome! Mmmmmm

Me reaction to fluorine appearing was "flourine you bastard" verbally

Liked for the content. Subscribed for the 90's safety video.

Regarding Isp, an honorable mention is the Gnom ICBM with 550 sec Isp at sea level and other air augmented rockets. Great show and many thanks for your work, Alexander.

YOOOO THE INTRO FEATURES SCIENCE IS FUN OFF THE PORTAL 2 OST? I bet that’s what they were thinking when they made this. And as a KSP player, everyone who has played it can confirm the first meme😂

I have a pdf of Ignition! on my phone that I had been reading on and off during lunch at work and some of the stories from that book are absolutely insane. It's highly technical and plenty of it goes over my head, but it's definitely worth a read for anyone who's interested in space travel and rockets.

Rocketdyne: "So anyways, we have made a rocket engine that is fueled with ANGER."

These chemicals are not only highly reactive, they're also incredibly toxic. I know of three young people who have suffered from cancer who lived near the Rocketdyne research center in California. I know this is off topic but it's just as important. Seeing a child undergo chemotherapy is heartbreaking.

Aside, GHS pictogram speedrun is now my new favourite thing.

"That's right, we're gonna build a rocket with a controlled metal fire. I already _hate_ that sentence but that's just the beginning..." Haha!

This is hands down my favorite KZfaq video

So you’re about to be the next Scott Manley, I heard. Subbed. Loved the nitpicking about choice of units and improper mixing of imperial and SI.

They have footage video of the "small" liquid fluorine leak and pictures of the large explosion aftermath at the testing grounds a 15 foot thick slab of reinforced metallic groute yeah the Apollo launch pad material ,(also used to hard block drag engines fyi) melted a hole through to bedrock 30feet past it and the associated support vehicles 50 feet away were almost in a pool because the heat melted them flat and oxidized the rubber and glass off them, because storage was next to the electric fork lift charger. The engine was used for a booster in a thermonuclear icbm they made a handful and cancelled the project. And if you are like wait this is before wire edm and and iscar silicon carbide ceramic tooling used to mill satellite and inconel. You are correct. That's because they used manually controlled 100k psi water jet that used 100% Hydrogen peroxide in a form of chemical milling.

Usually engineering is about achieving a goal under pretty restrictive conditions - safety, budgets, different norms and standards, secondary goals, time, etc. And usually i like to learn about projects made with restrictions, because what's fun in just throwing all already known cool stuff at a problem with unlimited budget? But not in the case of the period of atomic and space races - it had no brakes to no limit at all, so it became art by itself. And the only limit - time - was so strict, that it made everything so much -worse- better. I can't help but picturing it as a bunch of mekboiz doing the most unhinged and deranged stuff.

Can we take a moment to appreciate the stunningly perfect name that is Rocketdyne? It just rolls around the mouth…

28:41 Temperature doesn't measure velocity, but kinetic energy, which is related to the *square* of velocity. Reducing the temperature by a factor of 2/5, reduces the velocity by only the square root of that factor, or a bit under half. This becomes even less of a factor, once we consider that the main energy source is not the LH2/LF2, but the lithium added to its exhaust. (Speaking of: I do wonder what would happen if a second F2 injector were added past the lithium.)

Immediate like for Portal music.

Terrifying set of chemicals in that project. Great video.

It warms my heart that a video like this can get half a million views in two weeks. It (almost) renews my faith in mankind.

So awesome. I've studied rocketry for over 40 years and was aware of the use of lithium because it burns at like 13,000 F, enough to burn through anything that exists and the rule boost to ISP but didn't recall this tripropellant. The safety video is great. Also I don't know if they still have it but in the 80s they had a minute man guidance system the entire top section of the missile at Xavier University in Cincinnati that I got to play with. It was something to see all these computer boards you can pull out of slots just like apc in a radial pattern around the nose. I guess I was expecting custom soldered boards and a compact system and not a huge amount of extra space that was just empty around the boards. Something you might research is The accidental generation of a negative resister in that system causing power surges that had to be damped. I wish I was aware of that rumor in 1984 so I could have studied those boards more. It was just like in a store room and nobody paid any attention to it. I don't recall which Minuteman series that one was that I got to play with

lmao i just by accident own the "ignition" book. I got a few pages in before stopping but might pick it up when i have time after this!

hydroflouric acid exhaust decomposing the launch pad is simultaneousley tho funniest and most terrifying thing i can imagine

I can imagine the phone conversations between nasa and rocketdyne NASA: “Hey man I think you should make a safety rap where about half of it is telling employees not to damage the enviroment." Rocketdyne: “Sure.” NASA: “Also what about that tripropellant rocket engine you were working on that literally shoots HF and LiF out the back?” Rocketdyne: “May be marginally too dangerous to use on crewed flights."

I love the portal references Edit: I just got to the end. That outro video. Whaaat

thx for the polaroid. :x what a beauty. i remember it well and still own some pics from me as a kid. playing with rockets! :D

I don't think my jaw has dropped in horror this many times during a single video before. This is giving me pleasant memories of the Things I Won't Work With blog! Exotic chemistry is always crazy to hear about. That red exhaust plume is really thematic, I have to also say.

Kilopounds are typically referred to as kips, and are used because we have to deal with a bunch of legacy stuff and converting everything over to SI is a pain in the ass, so using kips offers some of the ease of metric without the need to convert everything over. It has associated units as well, such as ksi (kips per square inch) for stress